Sylvania



v e e h S m e e h S 2v H- E NN W G ON R L B .T WN m A (No Model.)

Patented Aug. 16, 1887.

' WITNESSES:

ffNToaj" r. Wadnnglun, 0.1:

(No Model.) 2 SheetsSheet 2.

A. W. BROWNB.

DENTAL ENGINE.

No. 368,187. Patented Aug. 16, 1887.

WiTNESSES:

NITED STATES Fries.

ARTHUR XV. BROVNE, OF lVESTFlELD, NElV YORK, ASSIGNOR TO THE S. S. WHITEDENTAL MANUFACTURING COMPANY, OF PHILADELPHIA, PENN- SYLVANIA.

DENTAL ENGINE.

SPECIFICATION forming part of Letters Patent No. 368,187, dated August16, 1887.

Application filed January 12, 1887. Serial No. 221,115. (No model.)Patented in England January 26, 1887', No. 1,279.

To all whom it may concern.-

Be it known that I, ARTHUR W. BROWNE, a citizen of the United States,residing at \Vcstfield, in the county of Richmond and State of New York,have invented certain new and useful Improvements in Dental Engines; andI do hereby declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and use the same, my said inventionhaving been patented in England January 26, 1887, as No. 1,278.

My invention relates to dental engines, wherein a rapid-revolving motionis imparted to a drivingshaft, and by said shaft to a toolholder, todrive an operating-tool carried by said tool-holder. The driving-shaftsof such engines are either flexible shaftssueh as wireeoil shaftsor aremade up of stiff sections of shafting connected by flexible or universaljoints, whereby the operating-tool driven by the shafting may be freelymoved about within certain limits to direct the tool to the proper pointand at the proper angle to do its work. The usual wire-coil shafts areopen to some objectionssnch as unsteadiness in operation and lack ofdurability while in the other class of shafts, made up of stiff sectionsunited by universal joints, there is generally either a stiffness in thejoints or the same liability to unsteady rotation as is observable withthe wire-coil shafts. These defects in the stiffsectioneduniversally-jointed shafts of previous constructions seem to be due toimperfections in the universal joints employed both. for the shaft-ingand the tubes or sleeves which envelop the shaft-sections.

The object of the first part of my present invention is to improve thedental engine as respects its stiffsectioned driving-shaft connectionsand bearings, whereby while the tool is free to be readily moved aboutto be directed to its work the shafting will be steadily and positivelydriven in whatever direction the tool may be operating with a likesteady and positive operation 011 the part of the tool driven by saidshafting, and whereby, also, the durability of the shaftin g will beincreased. A further object of this part of my invention is to improvethe organization of the driving shaft and lateral engine-arm so that theshafting may be readily supported horizontally by the top of the enginestandard or upright out of the way when not in use.

The next part of my invention relates to the manner of connecting thefoot-pedal and attachments to the base or tripod of the engine, so as toavoid tilting the engine upon an un even floor when the weight of theoperator is thrown upon the pedal in operating it.

The subjectanatter claimed herein as my invention will first bedescribed in detail as organized in the best way now known to me, andwill then be distinctly set forth at the close of this specification.

In the accompanying drawings, which illustrate so much of a dentalengine as is necessary to an ululerstainling of my present improvements,Figu re 1 is a side elevation of my improved engine, showingthe verticalstandard as adjusted slightly out of the perpendicular and the shaftingas supported out of the way, as when the engine is not in use. Fig. 2 isa detached view of a portion of the flexible or universal shading andits enveloping sleeves or bearings. Fig. 3 is an enlarged elevation of aportion of the shafting and enveloping-sleeves, one section thereofbeing bent backward, so as to lie substantially parallel with thesection beneath it. Fig. ii: is a similar view with one section of theshaft bent at right angles to the other. Fig. 5 is a similar view withthe outer shaft section at its extreme extended position. Fig. Gisavicwof the llexi ble or universaljoint of the shaft at right angles to theviews previouslyshown,showing an edge or plan view of theconnecting]inksbetwecn the enveloping sleeves or tubes ol'thejointedshaft ing. Fig. 7 is a longitudinal section through the engine-head andlateral. engine arm or sleeve, with a side view of the flexible oruniversal shafting to show the construction more clearly; and Fig. Sis aview of the vertical fork for securing and supporting the swingingsection of the driving'shaft and its sleeve and the hand-piece of theengine carried at the outer end thereof. Fig. 9 is a similar section tothat of Fig. 7, with a little dilfercncein detail, and showing the rearend of the driving-shaft as carrying abruslrwhecl to be rotated. Fig.10

ICO

is an enlarged view of the adjustable frictionconnection between thevertical enginestand ard and the base or tripod by which said standardmay be moved or adjusted out of the perpendicular and back again, asrequired; and Fig. 11 is a vertical section through saidfrictionconnection of the engine standard and base. Fig. 12 is anenlarged bottom plan of the jointed connection between the foot-treadleand base or tripod of the engine, and Fig. 13 is a cross-sectiontherethrough on the pivot-1i ne of the rocking pedal. Fig. 14 is a rearelevation of the improved engine.

The base A of the engine is preferably the tripod base, as usual, havingan upright or forked POStyAf, to receive the driving-pulley B. Saidpulley is mounted between the forks of the post A and keyed to revolvewith its crank-shaft O, the bearings of which are formed in the upperends of said post A. Thelower forked end of the vertical engine standardor upright D also straddles the driving-pulley B, and is fitted to rockor be adjusted on the extended ends or bosses of the forked end of thepost A in a common way. The said engine upright or standard D ismaintained in its adjusted position by a frictional connection with thepost A of the base or tripod A, and said connection is preferablyorganized by extending the lower forked ends of the engine-upright belowtheir pivotal connection with the post A,and fitting thereto on eachside of said post,preferably, (although one side would do,)friction-plates EE, the upper ends thereof being secured by screws 0 eto the lower ends of the upright, and the lower ends of said platesbeing secured to the post A or bosses thereof by screws 6 e, passingthrough longitudinal slots 0 c in said plates into the sides of saidpost A. By tightening said screws any required amount of friction can beexerted upon the lower end of the engine standard or upright D, and itmay consequently be readily rocked or adjusted to the desired verticalinclination, and will there remain until again adjusted to the normalperpendicular or other position desired.

Motion is imparted to the drivingpulley B through a crank, c, on the endof the crankshaft O, by a foot-treadle, F, and pitman G, as usual. Inorder to avoid any rocking or tilting of the engine upon an uneven floorwhen weight is thrown upon the foot-pedal, I pivot said pedaLF by itscrosswise-rocking pivot f to a base-piece, heel-plate,or arm, H, and inturn jointsaid base-piece, plate, or arm to one of the legs A of thebase or tripod A by a longitudinal pivotal connection, it, whereby thepedal F may rock or move independently upon and in the longitudinal lineof said leg A of the base or tripod. The weight, therefore, that isthrown upon the pedal is accommodated by the movement of the pedalandits connections without tilting the base or tripod.

The upright standard D of the engine is preferably asectional adjustableone, as usual, to secure the proper adjustmentsIand tension of thedriving-belt I, which passes from the driving-pulley B over the drivenpulley J of the engine-head K, mounted at the upper end of said engineupright or standard, as usual. Said engine-head is fitted to turn orswing around the upper end of the upright or stand ard D, as usual, bythe usual socket-and-pivot connection, (shown in Fig. 9,) and is fittedwith a bearing for the rear stiff section, L, of the revolvingdrivingshaft carrying the driven pulley J, as usual. Said pulley J iskeyed upon said driving-shaft section L,and rapidly revolves or drivesit when the driving-pulley B is revolved by the foot-treadl'e. An arm orsleeve, M, connected with or forming part of the engine-head K, extendsout laterally from said head, as usual, and being tubular forms abearing or bearings for the pulley-section L of the driving-shaft. Thisshaft-seetion L is a stiff shaft, and it extends to the outer tubularend, m, of the lateral arm or sleeve M, where it is connected by awire-coil drivingspring, N, with theiuner end of a second stiffshaft-section, O,which is also fitted to turn in a tubular sleeve orbearing, P, the outer end of which is preferably connected by the usualflexible wire-sleeve connection,Q,with the rear end of the usualhand-piece casing, R. The outer end of said second seetion,O, of thedriving-shaft is also connected by the usual wirecoil driving connectionto the rear or butt end of the tool-holder, fitted in said hand-piececasing to revolve said t00lholder and the operating-tool carried therebywhen the shaft is revolved.

7 It is desirable that the connection between the outer end of thesleeve or tubular lateral arm M and the inner end of the sleeve P shouldbe a universal connection, and such that in the movements of the sleeveP and shaft-section carried thereby relatively to the lateral arm andshaftsection L thereof there will be no straining or uneven bending orbuckling of the wire-coil connection N, and consequently no unsteady,jumping, or irregular motion in the driving-shaft, and consequently,also, none in the rotating operating-tool. The wirecoil or drivingspring N should take its natural curve or bend, and therebyavoidchanging the length of said spring N, either by stretching orcompressing it. To attain these ends I preferably form the adjacent endsof the two sleeves M I? each with a fork, and unite the opposing arms ormembers thereof together by a compound link-connection, whereby inbending one section of the driving-shaftand its enveloping-sleeverelatively to the other in operating with the engine the wire-coildrivingspring connectionN will always be bent substantially in the areof a circle, and without varying its length or contracting it when insuch bent position. The curves formed by said wire coil connection orspring Nin its various positions due to bending the stiff shaftsectionsare substantiallyisegments of circles of various radii, (see dottedlines, Figs. 4 and 5,) and the shafts occupy the positions of tangentsto the various circles. This compound link-connection consists,preferably, of four curved links, two of said links, S S, being pivotedat their inner or rear ends to opposite sides of the tubular lateral armor sleeve M, or the forked end thereof, and at their front ends to theopposite sides of the rear forked end of the sleeve P, and the other twolinks, T T, (the counterpart of the links S S,) being pivoted by theirrear ends to the front forked end of the sleeve M in advance of thepivots of the links S S with said sleeve, and by their front ends to theopposite sides of the forked end of the sleeve P in advance of thepivots of the front ends of the links S S with said sleeve 1. cross eachother,as shown,whereby the sleeves M P, with their containedshaft-sections, may be extended in approximately a straight line, asshown in Figs. 2 and 5, until limited by the abutment of thepivot-connections ofthe links, or may be bent toward each other througha range of motion substantially approximating to a parallel position, asshown, for example, in Figs. 1 and 7. This (in connection with theflexible connections at the butt-end of the handpieee and tool-holderthereof) gives all the motion of the driving-conncetions necessary toenable the handpiece and operating tool carried thereby to be freelymoved about to work at the point desired, and at the same time insuresdurability of the flexible driving spring connection with a steadyuniform rotation of the driving-shaft and operatiug'tool.

In order to give greater freedom of move ment to the hand-piece of theengine, and to provide for holding the front shaft-section, O, and itssleeve or bearing 1; out of the way when the engine is not in use, Iformthe front end, m, of the lateral engine arm, bearing, or

The links are curved and sleeve M in the form of a swiveling or turningsleeve, (see Fig. 7,) whereby the drivingshaft and the sleeve or bearingP, universal connections, and hand-piece may be turned around oraxially, or be rocked sidewise relatively to the rigid lateralenginearm, bearing, or sleeve M. By this organization, also, the front sleeve,P, and connected parts may be turned around relatively to the lateralenginearm M, and the said sleeve P and its contained shaft folded backparallel with said enginearm to fit in the vertical retaining-fork U,mounted on the engine-head, as clearly shown in Figs. 1. 7, and 14, soas to be heldout of the way of the operator when not in use.

I claim as my invention 1. The combination, with the enginebase, of thepedal fitted substantially parallel with one of the legs of said base,the heel-plate to which said pedal is pivoted, and the direct horizontallongitudinal pivotal connection of said heel-plate to said leg, wherebysaid pedal with its heel-plate may rock independently upon and in thelongitudinal line of said leg, substantially as described.

2. The engine-head or lateral arm provided with a vertical fork thereonto support the horizontallybeut driving-shaft, substantially asdescribed.

3. A compound joint for the sleeves or bearings ofa flexible oruniversal drivingshaft, said joint consisting of a double set of links,one of which is pivoted in advance of the other, substantially asdescribed.

In testimony whereof I affix my siguaturein presence of two witnesses.

ARTHUR \V. BROlVNE.

\Vitnesscs:

Mnnvitnn M. JonNs'roN, GILBERT S. BARNES.

